What's the point?

[OverThinker]

So if plants use LIGHT to produce oxygen, then why use a filter/powerhead? The filter would just cause more water agitation and thus decreasing CO2 intake/oxygen-producing anyway...

right?

[Church]

Yes and no. Yes, if you are going to the extent of injecting or adding CO2 into the water column, to increase the levels from what the atmospheric concentration is, then HOBs or bubblewands, anything that adds surface turbulence, will offgas the CO2 you went out of your way to add.

But no, using such filtration/water movement methods don't generally inhibit photosynthesis. As long as it remains a constant, it will probably match whatever the atmospheric CO2 concentration is consistently, therefore always having some CO2 available. If CO2 weren't present in the atmosphere, then terrestrial plants would not be able to photosynthesize, as they do in most places all throughout the world.

[OverThinker]

But WHY use a powerhead if the plants do it for youi?

[Church]

If the plants do what for you? Recirculate your water around the tank?

[bigboij]

Originally Posted by OverThinker

But WHY use a powerhead if the plants do it for youi?

ive always used powerheads to produce water flow, not add o2 to my tank.


maybe im doing it wrong?

[Church]

You can add oxygen to a tank with some powerheads, by using venturi effect, but I wouldn't say that a powerhead's primary objective in life is to aerate. I'd say it is for water movement.

Okay, overthinker, so now that I think I get what you were asking: that's a good question-- why would you use a powerhead to add oxygen to a planted tank?

[gmccreedy]

Adding O2 to a planted tank is not a bad thing. The plants don't use it, but the fish do. O2 does not displace CO2.

I use powerheads for circulation, not for O2 injection.

[redfalconf35]

Originally Posted by gmccreedy

Adding O2 to a planted tank is not a bad thing. The plants don't use MUCH OF it, but the fish do. O2 does not displace CO2.

I use powerheads for circulation, not for O2 injection.

small edit for technical correctness